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General => Ancestral Family Tree DNA Testing => Topic started by: Mart 'n' Al on Wednesday 15 May 19 15:59 BST (UK)

Title: Please help me interpret my DNA matches
Post by: Mart 'n' Al on Wednesday 15 May 19 15:59 BST (UK)
It's nearly a year since I got my DNA results, and all I've done is confirm that two half-first-cousins, who I knew about from my paper research, were definitely related to me as expected. On Monday I finally contacted my third match, with whom I share 92cM including one 76cM segment. Almost by return email I heard from a lady JH who told me that her great grandfather FH came from the same Durham mining village as my great-grandmother, JA. This sounded very significant, as her great-grandfather was 20 at the same time as my great grandmother's mother was 20.  That seemed an open and shut case as to who was the father of my great grandmother, who married someone else three years later.

Buoyed by this success yesterday I contacted the fourth match on my list, HC, somebody with whom I share 52cM. He very quickly replied and told me that his great grandmother MH came from the same village again, and was the sister of the aforementioned gentleman, FH. This exonerated FH from being my great grandmother's father, as our most recent common ancestor would have to be at least one generation further back.

This now suggests that the father of MH and FH could be the father of my great grandmother, however he would have been 63 when she was 20. Possible but unlikely.

JH and HC, the two descendants share 89cM with each other.

I welcome any further comments, suggestions, fantasies or informed ideas.

Martin
Title: Re: Please help me interpret my DNA matches
Post by: Flemming on Wednesday 15 May 19 17:21 BST (UK)
Hello Martin, just sketched the theoretical connection on paper and it looks like you and JH could be half second cousins once removed - DNA Painter average for this is 83cM.

HC could be a third cousin and the DNA Painter average for this is 74cM.

Could 92cM for the former and 52cM for the latter not be acceptable variances of the average?
Title: Re: Please help me interpret my DNA matches
Post by: Mart 'n' Al on Wednesday 15 May 19 18:40 BST (UK)
Flemming, I agree with all you say.  If we share great great grandparents we could be 2nd cousins.  I'm just hoping that someone can help focus on who dallied with my great great grannie!

My half first cousin, who is, like me, also the great grandson of JA, shares 54cM with JH and 27cM with HC, but I don't think that that tells us anything extra.

After a year of apathy regarding contacting my matches, I was stunned to get two replies so quickly, mentioning, unprompted, the village where I strongly believed my great grandmother was born.  We just couldn't quite be sure.  Now it is almost certain, but also I get a new mystery, regarding her father.  We had assumed that it was the man who married her mother two years later, and brought her up, but I think this saint is ruled out.  See also:

https://www.rootschat.com/forum/index.php?topic=766975.msg

https://www.rootschat.com/forum/index.php?topic=770198.msg

https://www.rootschat.com/forum/index.php?topic=794673.msg

It's been a long struggle.

Martin
Title: Re: Please help me interpret my DNA matches
Post by: Flemming on Wednesday 15 May 19 19:07 BST (UK)
Hello Martin, I'm uploading a tree (I hope). If this is correct, I think the cMs might fit for FH to be the father. What do you think?
Title: Re: Please help me interpret my DNA matches
Post by: Flemming on Wednesday 15 May 19 19:10 BST (UK)
Trying a jpeg...

Title: Re: Please help me interpret my DNA matches
Post by: Mart 'n' Al on Wednesday 15 May 19 19:53 BST (UK)
Flemming, that is very neat.  I originally suspected FH, but that was before I knew about the 51cM match with HC.  If FH is the father of JA, why do I have the 51 cM match, effectively to MH and FH's parents?  It seems a lot as 'background'.  Or am I wrong - it would be quite possible!

Martin
Title: Re: Please help me interpret my DNA matches
Post by: Flemming on Wednesday 15 May 19 20:04 BST (UK)
Well, I'm only reading off the cM tool on DNA Painter (see below) which says 48cM is the average for 3C1R - and the range is 0-173cM. If you type 52cM in the top box, one of the top relationships is 3C1R with a 29.75% probability.

https://dnapainter.com/tools/sharedcmv4
Title: Re: Please help me interpret my DNA matches
Post by: Mart 'n' Al on Wednesday 15 May 19 20:36 BST (UK)
Flemming, yes, I'm doing the same, but if a father/grandfather/g-grandfather share progressively 50% less each generation back, i.e. 3487/1766/881, shouldn't I expect a great great grandfather to share about half the last value, 440?

Or at least in the range of 150-500?  It appears that the upper and lower limits are about 30% for each generation back.

Thanks for your continued help.

Martin
Title: Re: Please help me interpret my DNA matches
Post by: Flemming on Wednesday 15 May 19 20:48 BST (UK)
I'm finding that DNA isn't that logical  ;D  I'm working with two shared matches now that are bizarre. A known 2C2R shares just 9cM with me. A 2C1R in the same line shares 120cM with me. They share 105cm with each other. Bonkers.

I think the DNA Painter averages are a really good steer.

And have you watched this video that someone posted in another thread? Really helped me understand how DNA doesn't split evenly down the generations.

https://www.youtube.com/watch?v=nlmK0X3I1Lo
Title: Re: Please help me interpret my DNA matches
Post by: Mart 'n' Al on Wednesday 15 May 19 21:06 BST (UK)
I will watch it again.  I think I posted a link to it last year after being impressed by it., and got lambasted for praising it so highly.

I agree that it is hit and miss, but being beyond The Outer Limits troubles me.  I hope we get more comments.

Martin